Biota (BTA)

Shares in drug developer Biota have fallen more than 34 per cent from a 12-month high of $3.34 and in the past five sessions the stock has dropped 7.5 per cent.

Biota shares surged 495 per cent in 2009, driven by expectations of higher royalty payments from increased sales of its Relenza anti-viral drug.

Last year, governments increased their orders for anti-viral drugs after swine flu broke out, but with the threat of swine flu diminishing it appears investors have decided to ditch the stock and book profits.

In an attempt to diversify its business, Biota, agreed to buy two companies developing treatments to fight antibiotic-resistant “super bugs" late last year.

Biota said it would acquire MaxThera for $US1.5 million ($1.6 million) and planned to invest up to $US15 million in the Boston-based company over the next three to five years. MaxThera develops antibacterial compounds to treat bacterial infections that are resistant to existing antibiotics.